In many conventional sailboats, the luff edge of the mainsail is slidably affixed to the mast. More particularly, a bolt rope is secured to that edge of the sail by a bolt tape engaged around the rope and stitched to the sail at opposite sides thereof. To facilitate raising and lowering the sail on the mast, the boat rope engages in a slot or track formed in the aft wall of the mast, the end of the boat rope at the upper end of the sail being introduced into the slot through an enlarged entrance opening at the lower end of the slot just above the boom. The head of the sail is connected to a main halyard and hoisted up the mast by the halyard with the bolt rope feeding into the slot through the entrance opening.
Due to the fact that the lowered sail is folded or bunched together at the boom, the luff edge of the sail containing the bolt rope is not necessarily aligned with the mast or more particularly its slot. Accordingly, as the sail is being raised, the bolt rope does not automatically feed properly into its slot in the mast. Consequently, someone usually has to be present at the foot of the mast to guide the bolt rope into that slot by hand to prevent its becoming jammed.
Some attempts have been made to alleviate this problem by providing a specially shaped insert in the mast at the entrance to the bolt rope slot. However, installation of that insert involves cutting a hole in the mast at the slot entrance in which to seat the insert. Accordingly, as a practical matter, that fixture must be installed in the mast by the mast supplier at its plant. It cannot be retrofit on existing masts on working boats. Also such inserts, being cast metal parts, are relatively expensive to make.